1. Field of the Disclosure
The embodiments described herein relate to a multiple stage orbital delivery vehicle that uses tractor propulsion.
2. Description of the Related Art
Multiple stage rockets have been used to launch orbiting devices, such as satellites, in the past. These have included both ground and air launched systems. However, the multiple stage rockets are complex, requiring both engines and control actuation systems to steer each stage. These control systems typically utilize actuators in both the pitch and yaw control planes to point the engine nozzle in a method referred to as thrust vector control, and require either electrical or hydraulic power sources which are added cost and complexity. Each stage has to be ignited as the lower stage is dropped from the vehicle. If a stage fails to ignite, the vehicle may not be successful in delivering the satellite into orbit. Further, conventional small multiple stage rockets often use solid propellant stages, which are heavier, less efficient, and more expensive than liquid propellant. Once solid propellant has been ignited it is difficult to stop the combustion until the entire propellant has been consumed unless higher complexity pintle techniques are used. Varying thrust or throttling the thrust level is also a challenge for solid propellant rocket motors.
Further, launch vehicle overall reliability is a function of part count, and increasing the launch vehicle reliability needs to be addressed by either increasing the reliability of individual components with an associated expense, or else reducing the number of components.